The invention relates to a belt saw guiding device for a belt saw machine, in particular to a guiding device which changes the running course of the belt saw in case a work piece of hard material is cut continuously in one direction by the belt saw.
A conventional belt saw machine comprises an arm fixed at one end to the machine bed and a pair of pulleys rotatably attached to the arm. Since the belt saw is driven by the pulleys, its halves run parallel in the opposite directions, facing each other. It is therefore impossible with such a machine to cut a work piece into smaller pieces each having a length more than the diameter of the pulleys. If the work piece is laid so as to obtain a longer piece, it will be cut into three pieces at a time by the saw halves. To obtain a longer piece with such a machine, the work table is inclined and the saw is forcedly guided in the direction perpendicular to the table. Even if this cumbersome method is employed, the resultant piece remains several times as short as the overall length of the belt saw machine. This means that if the work piece is to be cut into a little longer pieces, the machine has to be made proportionally huge.
If the machine is made massive for such a reason, it occupies much space in the factory and its cost becomes inevitably high. At any rate its size is practically limited for mechanical and economical reason.